___ anchors have an unthreaded hole into which a wood or sheet metal screw is driven.

___ anchors have an unthreaded hole into which a wood or sheet metal screw is driven.

• A. Nylon anchors
• B. Lead anchors
• C. Plastic anchors
• D. Metal anchors

Answer: (B)

Lead anchors work like this: they are made of soft metal and sit in a drilled hole with a smooth, unthreaded bore. When you drive a wood or sheet metal screw into that bore, the screw threads cut into the lead itself. As the screw cuts threads and tightens, the anchor expands against the sides of the hole, creating a secure grip in the surrounding material. This expansion-by-screw mechanism is what makes lead anchors the best match for the description of an unthreaded hole into which a screw is driven.

Lead anchors work like this: they are made of soft metal and sit in a drilled hole with a smooth, unthreaded bore. When you drive a wood or sheet metal screw into that bore, the screw threads cut into the lead itself. As the screw cuts threads and tightens, the anchor expands against the sides of the hole, creating a secure grip in the surrounding material. This expansion-by-screw mechanism is what makes lead anchors the best match for the description of an unthreaded hole into which a screw is driven.